Man-Machine Interface codes, or MMI codes, are specific sequences of numbers and symbols that perform functions or retrieve information. For example, use ##232339## to perform a Wi-Fi network test. However, MMI codes don’t always work; this article covers all of the best ways to fix invalid code MMI warnings and prevent them from happening again in the future.
How to Fix Connection Issue or Invalid MMI Code Error in Android [Updated 2024]
Here are all the most effective ways to fix an invalid code MMI error warning and prevent it from happening again. It’s best to go through them in the order presented, as we’ve sorted them from the easiest and simplest to the most complex.
Please check the MMI code again. Make sure you have entered the MMI code correctly.
Check the compatibility of the MMI code. Your smartphone manufacturer’s website and your mobile carrier’s website should have a full list of compatible MMI codes for your Android. The manual that came with your smartphone may also have a list of approved codes.
